(a) Field of the Invention
The present invention relates to a three-dimensional display device, and in particular, to an autostereoscopic three-dimensional display device using a parallax barrier and a driving method thereof.
(b) Description of the Related Art
Generally, three-dimensional display devices supply different views to the left and right eyes of a user such that the user can have a depth perception and a stereoscopic perception of the viewed image.
The three-dimensional display device may be categorized as a stereoscopic display device where the user should wear viewing aids such as polarizing glasses, or an autostereoscopic display device where the user can see the desired three-dimensional image without wearing such viewing aids.
A common autostereoscopic display device utilizes an optical separation element, such as a lenticular lens, a parallax barrier, or a microlens array, to spatially separate or isolate the left-eye image part and the right-eye image part displayed at an image display unit in the directions of the left and right eyes of the user, respectively.
In particular, the parallax barrier may be formed with a liquid crystal shutter utilizing a transmission type of liquid crystal display, and in this case, it may be converted between a two-dimensional mode and a three-dimensional mode. Thus the parallax barrier can be easily applied to laptop computers or cellular phones.
Generally, the parallax barrier includes stripe-shaped light interception portions and light transmission portions. The parallax barrier selectively separates left and right eye images displayed at the image display unit through the light transmission portions such that the left and right eye images are respectively provided to the left and right eyes of the user.
The light transmission portions are arranged such that each of the light transmission portions corresponds to at least two of the pixels.
The most conventional type of three-dimensional display device using the parallax barrier forms a three-dimensional image in such a way that the left and right images displayed at the image display unit are separated through the parallax barrier and form a three-dimensional image.
In this device, the image is separated into 2-viewpoint (“two-viewpoint”) images. However, there is a problem with this 2-viewpoint type of three-dimensional display device in that the visible range is very small, and the screen should be viewed while the user maintains a certain position in order to perceive the three-dimensional image.
Therefore, researches on a type of three-dimensional display device that separates an image into three or more multi-viewpoint images have been proceeding in order to obtain more natural stereoscopic perception and to solve the small visible range problem. However, in the case of the multi-viewpoint type, there is a problem of lower resolution in comparison with the 2-viewpoint type.
Hence, a problem with the conventional three-dimensional display devices is that it is difficult to overcome the disadvantages of the multi-viewpoint mode and the 2-viewpoint mode in the same device.